By Wolf Blitzer, CNN (CNN) -- And now there are four Republican presidential candidates left in the contest. They were all on the stage Thursday night at the tough CNN debate in South Carolina. One of them will almost certainly face President Barack Obama in November.

updated 5:20 PM EST, Fri January 6, 2012 (CNN) -- GOP frontrunner Mitt Romney's campaign stepped up its criticism of conservative challenger Rick Santorum on Friday, continuing to hit the former Pennsylvania senator on his spending record while in Congress.

(CNN) - President Obama is now in full re-election campaign mode. If there was any doubt, just check out the campaign speeches he delivered Wednesday night at three separate fundraising events in Chicago. "I've said before, I'm not a perfect man," he told one Chicago group. "I'm not a perfect president.

(CNN) - Jon Huntsman is now a former Republican presidential candidate. And, like former Minnesota Gov. Tim Pawlenty who dropped out after a poor showing in the Iowa straw poll last summer, Huntsman is endorsing Mitt Romney. Never mind that Huntsman said some negative things about Romney during his unsuccessful campaign.

By Wolf Blitzer, CNN (CNN) -- A week ago, the Gallup daily tracking poll of registered Republicans around the country had Mitt Romney at 37% with Newt Gingrich at only 14%. Guess what? That 23-point spread has now disappeared. The new nationwide Gallup numbers: Romney 29% to Gingrich’s 28%.

(CNN) - Allow me to insert some caution in assessing the Republican presidential campaign. As much as so many folks are already suggesting that Mitt Romney has it all but wrapped up, let me suggest that it's not over yet. Sure Romney has a solid organization with lots of campaign cash.

Charleston, South Carolina (CNN) - Here are a few things I will be looking for in Thursday night's CNN Southern Republican Presidential Debate: The four remaining candidates have been beating up on each other in recent days. Will they have the guts to blast their opponents when they are standing right next to them?

By CNN's Wolf Blitzer (CNN) - I know it will probably sound weird, but I admire these politicians who put themselves out there before the American public knowing full well that all their warts will be exposed big time. Most of them already have lots of money.

Atlanta (CNN) - Even while I'm here at the CNN Election Center in Atlanta getting ready for the Iowa caucuses, I'm hearing disturbing murmurings from my national security sources in Washington about North Korea. They clearly don't know what the new leadership in Pyongyang is going to do, but they are bracing for a possible provocation on the Korean peninsula.

(CNN) - Newt Gingrich said Tuesday he wouldn't vote for Ron Paul if the Texas congressman won the 2012 GOP nomination. Speaking to CNN's Wolf Blitzer, Gingrich slammed Paul as out of line with mainstream Republican viewpoints, including his stance on Israel, Iran, and September 11.

Get ready for a really ugly general election presidential campaign. The negative ads are going to be intense no matter who wins the Republican nomination. If you had any doubts about the effectiveness of negative attack ads, just take a look at what has happened in Iowa these past few weeks.

(CNN) - I'm just back from a couple days in Iowa, where I had a chance to sit down with Mitt Romney, Newt Gingrich and Rick Santorum. I also spoke with Iowans who are planning on attending Tuesday night's caucuses. Here are some impressions: Romney is confident about his chances of winning in Iowa and then in New Hampshire.

(CNN) - I am beginning to suspect that Iraq could wind up following Yugoslavia's example. As you know, there once was a country called Yugoslavia. It had several distinct provinces based on ethnic differences: Bosnia and Herzegovina, Croatia, Macedonia, Montenegro, Slovenia, Kosovo and Serbia. You get the point.

Dubuque, Iowa (CNN) - So how many tickets will there be out of the Iowa caucuses? I know the three front-runners - Mitt Romney, Newt Gingrich and Ron Paul - are all set for New Hampshire. Jon Huntsman has basically ignored Iowa and is focusing all his attention on New Hampshire.

By Wolf Blitzer, CNN (CNN) -- I spoke with former Pakistani President Pervez Musharraf, who made it clear that he’s going back to Pakistan at the end of this month, despite authorities’ threat of arrest. “Yes, indeed,” he told me from Dubai. “I am blessed to go back.

By Wolf Blitzer, CNN Charleston, South Carolina (CNN) – All of a sudden, this contest is getting very exciting. In these final days before Saturday’s Republican presidential primary, the gap between Mitt Romney and Newt Gingrich seems to be narrowing -- if you believe the latest polls.

CNN's Wolf Blitzer spoke with former Pennsylvania Sen. Rick Santorum about his thoughts on the updated vote count from Iowa. A highlight from the interview is after the jump; please visit http://cnnpressroom.blogs.cnn.com for additional information. This full interview will air on The Situation Room with Wolf Blitzer on CNN 4-6 p.m.

(CNN) - Because we've seen so many ups and downs in this race for the Republican presidential nomination, I'd like to recommend that we all take a deep breath and let the process fully play itself out. I say this because so many pundits already assume that Mitt Romney has it in the bag.